The Connection Between Sleep and Emotional Memory

By Eric Cohen, MD

Published Aug 27, 2013



There is a particular mechanism in the brain that allows it to take care of emotional memory while you sleep. There is presently a sleep aid that is frequently obtained by prescription which can actually increase the recollection and reaction of memories that are associated with negative emotions.

The problem is that people who are suffering from Post-Traumatic Stress Disorder (PTSD) or other types of anxiety often need sleep aids. A popular one, Ambien, may have a negative side effect that could negate the positive effects of the medication.

The part of sleep that we are talking about is called spindles. These are little bursts of activity in the brain that may not even last as long as a second. When these occur during a particular stage of sleep, it can be important for storing emotional memory for easy recall. Unfortunately, when it comes to certain medications, this process seems to focus on negative emotional memories.

These same spindles were previously proved to be vital to shuffling things from short-term to long-term memory, so this study further verifies their connection to memory. The same study also revealed for the first time that prescription medications working in a person that is asleep can actually have an effect on memory. Emotional memory was thought to be a separate process that had more to do with REM sleep.

Basically, in the test, a couple of different sleep aids were provided to subjects. The results showed that REM isn’t when the emotional memories are stored; it is during the occurrence of spindles.

After taking the medications as directed, pictures designed to create strong emotional connections were displayed. Those taking the medication, however, focused on the negative pictures that were shown. Thus, when the patient took sleeping meds, or an anti-anxiety drug classified as a benzodiazepine, they had more negative memories that could be brought to the forefront more easily.

Researchers were shocked by the results. If anti-anxiety drugs and sleep aids can cause a person who already has a problem focusing on the negative to have these memories aroused more frequently and realistically, it would seem to defeat that primary role of the medication in the first place.

Researchers now want the opportunity to do further studies so as to prove that the negative side effects of certain sleep and anxiety drugs may alter the usefulness of the drugs. Of course, always be sure to consult your physician before deciding to come off of a medication that was prescribed.